In the past, a variety of devices have been used to improve performance of oil filters. Some devices involve changes within the filter housing itself to improve its ability to remove ferrous shavings which circulate in the engine oil system. U.S. Pat. No. 4,592,836 issued June 3, 1986, illustrates an engine oil filter involving an electrostatic generator to produce an electrostatic field between the casing body of the engine oil cleaner body and the polar plate. The charged metallic particles are then absorbed on the surface of the corrugated porous papaer board.
U.S. Pat. No. 3,035,703 illustrates the use of a combination of permanent magnets mounted within a mesh to attract magnetic particles into the mesh along the periphery of the filter. U.S. Pat. No. 2,838,179 operates along similar principals as those disclosed in U.S. Pat. No. 3,035,703.
U.S. Pat. No. 3,121,683 illustrates the use of a combination of a conveyer for lubricating oil containing machine cuttings coupled with the use of magnets to separate the cuttings from the oil.
U.S. Pat. No, 4,329,231 is a thermally insulating housing to be slipped over gasoline filters to shield them from heat emanating from the engine.
U.S. Pat. No. 4,218,320 issued Aug. 19, 1980, illustrates the use of an electric coil mounted near the bottom of a spin-on oil filter for the purpose of attacting suspended magnetic particles within the circulating oil system.
U.S. Pat. No. 3,460,679 issued Aug. 12, 1969, illustrates a belt suitable for mounting over a spin-on oil filter which includes a magnet thereon.
U.S. Pat. No. 3,480,145 issued Nov. 25, 1969, illustrates an assembly adapted to frictionally magnetically and slideably engage a filter can to attract magnetic particles circulating in the oil from an internal combustion engine which cannot be filtered by mechanical means such as particles which may pass through a ceramic filter.